687669551461 has 16 divisors (see below), whose sum is σ = 712540105200. Its totient is φ = 663149306880.

The previous prime is 687669551447. The next prime is 687669551501. The reversal of 687669551461 is 164155966786.

It can be written as a sum of positive squares in 8 ways, for example, as 38083522500 + 649586028961 = 195150^2 + 805969^2 .

It is a de Polignac number, because none of the positive numbers 2^k-687669551461 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 687669551393 and 687669551402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687669551761) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2406205 + ... + 2676781.

It is an arithmetic number, because the mean of its divisors is an integer number (44533756575).

Almost surely, 2^687669551461 is an apocalyptic number.

It is an amenable number.

687669551461 is a deficient number, since it is larger than the sum of its proper divisors (24870553739).

687669551461 is a wasteful number, since it uses less digits than its factorization.

687669551461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271224.

The product of its digits is 65318400, while the sum is 64.

The spelling of 687669551461 in words is "six hundred eighty-seven billion, six hundred sixty-nine million, five hundred fifty-one thousand, four hundred sixty-one".